Magnetic resonance imaging of suprascapular nerve palsy.

In magnetic resonance imaging of peripheral nerve palsy, changes of signal intensity are often found in paralyzed muscles. The purpose of this report is to clarify the relation between magnetic resonance imaging findings and clinical examination in suprascapular nerve palsy. The subjects were 12 patients with suprascapular nerve palsy who underwent magnetic resonance imaging examinations. In 9 of 12 cases ganglion cysts were found at the spinoglenoid notches. On T1-weighted images the signal intensity of infraspinatus muscle was high in four cases but normal in the supraspinatus muscle in all cases. On T2-weighted images the signal intensity of infraspinatus muscle was high in six cases, and that for supraspinatus muscle was high in one case. In two cases the high intensity of palsied muscles became normal after the palsy recovered. Magnetic resonance imaging is a useful examination of peripheral nerve palsy not only for the detection of ganglion cysts but also for assessing the stage of paralysis.